The present application describes systems and techniques relating to image modification, for example, modifying a digital image to improve display qualities or to obtain creative effects.
One conventional technique for modifying images involves using an image adjustment interface to modify image data on a pixel-by-pixel basis, such as to change image brightness, contrast, color, and so on. The PHOTOSHOP® image editing software, provided by Adobe Systems Incorporated of San Jose, Calif., offers such user interfaces (e.g., curves, levels, sliders), which can be used to define a mapping from a first set of pixel values to a second set of pixel values. When the mapping is applied to an image, the appearance of the image is changed accordingly.
Traditional techniques for modifying images also include image enhancement techniques used to address recurring visual anomalies, such as by obtaining dynamic range compression. Land's retinex theory has been used in a number of image enhancement techniques that apply a defined modification to an image to address dynamic range and color constancy issues. Other defined techniques for adjusting shadow and highlight detail in images are also available. For example, one technique can assist in removing shadows from images and involves duplicating, blurring and inverting an image, followed by combining the image with the original image in Color Dodge mode in PHOTOSHOP® software. Although the sequence of steps in this technique may be considered relatively strange, they can produce useful results in adjusting shadow and highlight detail in images.